This invention relates to vehicular drum-type brakes, and more specifically to a drum brake wear sensor system which senses break lining wear and lights a warning light when the lining wear reaches a predetermined amount.
Most motor vehicles utilize drum-type hydraulic brake systems. Included are industrial vehicles like fork lifts, tugs, cranes as well as trucks and passenger vehicles or automobiles. Drum-type brakes require regular inspection to permit replacement of the brake lining before the rivets which attach the lining to the brake backing shoes engage the brake drum, scoring the drum. In the case of bonded brakes the brake shoes themselves will engage the drum with excessive wear of the lining. Due to the complexity and expense of inspecting brakes on many trucks and industrial vehicles the brakes are usually replaced either prematurely or after the drum and shoes have been ruined because of metal-to-metal contact as a result of excessive brake lining wear.
It is a principle object of this invention to reduce premature brake drum wear caused by brake rivets and backing shoes engaging one another as a result of excessive wearing of the brake lining.
A further object of this invention is to minimize vehicular maintenance costs by eliminating the necessity of inspecting drum-type brakes for brake lining wear.
It is a still further object of this invention to provide a brake wear sensor which can be applied either at the time of original equipment manufacture or as an after market device by installing the sensor in an existing fastener which attaches the lining to the brake backing shoe.